Laboratory findings revealed severe thrombocytopenia, microangiopathic hemolytic anemia, markedly elevated IL-6, and critically reduced ADAMTS13 activity (5.41%) without an inhibitor by a Bethesda assay, in a sample obtained before the first therapeutic plasma exchange (TPE) and before any fresh frozen plasma (FFP) infusion, suggesting a cytokine-driven thrombotic thrombocytopenic purpura (TTP)-like syndrome. The gene discussed is ADAMTS13; the disease is congenital thrombotic thrombocytopenic purpura.